[TA Forbes]

Yes, a beautiful set!

It is always a thrill to get one of these early sets working.

[Groundhog74]

Picked up a Brandes Table Talker horn speaker on the bay this weekend. I checked the transformers as well as the grid leak resistor and they seem fine. Hopefully it'll fire right up. While I wait for the speaker to arrive I'll work on the batteries. If I get it going, I'll look into the battery eliminator.

[Gene Pederson]

You've got that looking really nice!! Great find!

Gene

[keithw]

Great looking set! I have been working on a very similar Sonora/Splitdorf from 1925 and found a little tuning trick that you might like. When all there tuning knobs are peaked it just doesn't sound quite right. I swept the audio response and found it peaked about 1200 Hz then dropped off quickly as the frequency goes up. After peaking all three tuning knobs set the second knob 1/2 count lower and the third 1/2 count higher. This opens up the bandwidth a little bit and flattens out the audio frequency response.

We are running batteries. For "A" we have a 6v 12 Ah SLA lead acid on the way, currently using a bench supply. For the "B" using 4 of the 22.5 volt batteries the size of 9 volt batteries with a tap at 22.5 v and 90 v. For the "C" using 3 each 1.5 v c batteries.

Once you get it sorted out I think you will be surprised at how good it sounds.

keithw

[Groundhog74]

Finally won an eBay auction and got the 01A tubes I needed. I rigged up some 9v batteries to provide the 45 and 90v I needed, and decided to try my battery tender set for 6 v as an "A" supply...I know that's not right, but wanted to make sure the radio worked at all before I invested more money. After I finally figured out the right combination with the battery hook ups, I was receiving, but with very low volume. In the headset I could hear ok, but low, the speaker was barely audible. Later, I added a "C" battery using 2 AA batteries, and added a slightly better antenna. Volume was better, headset was fairly loud, the speaker was what I would call lower mid-range volume wise. After about 5 minutes of operation my battery tender would go into a fault and shut everything down until I turned it off and reset it. The tender is rated at 1.5 amps and probably sees the radios current draw of 1.25 to 1.5 amps as a battery problem and faults out. Possibly the voltage was low too also, I did not check it with the radio on. Today I picked up a proper dual 30 v dc power supply and will try it. It will handle the load with room to spare. Also, I believe a longer, higher antenna will make a difference. Right now I'm using about 20 feet of wire strung around the room.
With no idea how to tune it, I was receiving WOWO out of Fort Wayne Indiana which is about 75 miles from here and a very strong station that I listen to a lot. Overall I am very happy with this 50 dollar antique store find. With the speaker, tubes and miscellaneous stuff I currently am into this rig for around $275. For a really clean, working 1920's TRF With a working horn speaker I don't feel I got hurt money wise too bad. I will get a battery eliminator some time soon as I think I may be in the market for more 1920's sets in the future. I can see where they could get addictive.

[TA Forbes]

Agree, getting one of these early sets is a thrill! I recently did the same with an AK 30 after reading this and other threads. I would like to do the same with my AR-812.

The $ put into a set is a deeply personal decision. If it is worth it to the owner of the set, then it is worth the satisfaction the owner gets from it.

[Groundhog74]

Hooked everything up again as I did last time but with the new power supply. Performance was about the same. I then cranked up all filament voltage dials from the initial setting of 70 as per the instructions to 90. Volume was much better and I was receiving stations from all over. I even was receiving Cincinnatti clearly. Volume was what I would describe as high medium. Clearly audible in a medium sized room as long as background noise is minimum. When the weather clears up, I will try a much longer antenna strung outside. I am not sure how loud these sets played when new. I'm sure the speaker is probably a little weak after 80+ years as well. I did notice that I only get sound out of the left phone jack. The right one seems dead. I'll have to re-check that output coil. I did move a couple tubes around and that made no change with the dead jack. Overall I am really satisfied. Time to start shopping for a battery eliminator.......and my next 1920's set.

[exray]

I'm a fan of lots of knobs. I've got one set of headphones here that have, for whatever fault, different audio characteristics between the two phone elements. I can slowly swish through a signal with a 3-dialer and it seems like stereo as the audio goes from one ear to the other. Once you actually do that then the sweet spot sounds like stereo!

Your dead jack may be just poor connection. Many configurations killed the voltage to the unused stage(s) further downstream and generally a jack on the left would preceed a right-side jack so look further. Could be there's a poor connection on the left-side jack contacts or a problem in the next stage (like a bad xfmr?)

Another tidbit...It has been documented that 01As have a little burst of sensitivity and better s/n ratio down around 3.6/3.8 filament volts. Leutz was one of the first to write about it back in the 20s and his book Modern Radio Reception has graphs, etc showing the effect.

And C voltage can be pretty persnickety depending on the state of the tubes and if you're really picky there are noticeable differences at various rheo levels of A voltage as well as B+ voltage.

These are fun radios

[Radioroslyn]

Boy what a nice looking set!!!
I'll mention in passing and this goes for any battery sets older like your's or portable if you run it on batteries after you have done all of the electronics turn the set off and measure current from B- to - on the B battery. You want to be sure that your set isn't drawing any current when it's turned off. If it is it will run your B batteries down or kill them.
I had a Silvertone Neotrodyne that had a leaking bypass cap and that little son of a gun ran down 3 big old 45vB batteries I had bought new for like $15 or 20 this was back in the 1970's.
Great Job!
Terry